Diatoms as Bioindicators of Environmental Change in Cape Herschel and Pim Island (Nunavut, Canada) Ponds
Thesis (Master, Biology) -- Queen's University, 2016-02-25 13:36:41.386 The High Arctic is especially sensitive to climatic change, but typically direct long-term monitoring data are lacking. Instead, paleolimnological approaches are now widely used to reconstruct past environmental changes. In...
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ftqueensuniv:oai:qspace.library.queensu.ca:1974/14084 2023-05-15T14:29:39+02:00 Diatoms as Bioindicators of Environmental Change in Cape Herschel and Pim Island (Nunavut, Canada) Ponds Melnik-Proud, Rachael Smol, John P. Biology 2016-02-25 13:36:41.386 http://hdl.handle.net/1974/14084 eng eng Canadian theses http://hdl.handle.net/1974/14084 Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada ProQuest PhD and Master's Theses International Dissemination Agreement Intellectual Property Guidelines at Queen's University Copying and Preserving Your Thesis Creative Commons - Attribution - CC BY This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. CC-BY Paleolimnology High Arctic Cape Herschel Diatoms thesis 2016 ftqueensuniv 2020-12-29T09:08:44Z Thesis (Master, Biology) -- Queen's University, 2016-02-25 13:36:41.386 The High Arctic is especially sensitive to climatic change, but typically direct long-term monitoring data are lacking. Instead, paleolimnological approaches are now widely used to reconstruct past environmental changes. In particular, sub-fossil diatoms are well-established paleo-indicators of past limnological conditions. My thesis research is focused on Cape Herschel, east-central Ellesmere Island, as the numerous ponds in this region are well-studied and encompass a spectrum of morphometry, microclimate, and vegetation. This thesis has two separate but related chapters. The first chapter documents recent limnological changes and associated epilithic and surface sediment diatom assemblages from five well-studied Cape Herschel ponds, sampled on a semi-regular basis from 1987-2011. Diatom trends were reconstructed and compared to a suite of water-chemistry variables. Increased species diversity in both epilithic and surface sediments were observed, indicative of warming and associated longer ice-free growing seasons, allowing for the establishment of taxa with more complex lifestyles. These ponds also experienced increases in conductivity, dissolved organic carbon, dissolved inorganic carbon, and pH over the sampling period. Trends in diatom assemblage were more pronounced in epilithic samples (representing year-to year changes), when compared to surface sediments (an integration of multiple years of diatom production). Diatom assemblages from the Cape Herschel ponds were then compared to previously studied and near-by (~10 km away) Pim Island ponds. The latter ponds had a more muted response to recent climate warming, likely due to their colder microclimates linked to their close proximity to near-shore sea ice. The second chapter focused on diatom assemblages from sediment cores recovered from two Pim Island ponds. Diatom assemblages in both sediment cores recorded a recent shift from low diversity benthic fragilarioids to more diverse assemblages dominated by epiphytic taxa, with more complex growth forms. This shift in taxa and diversity reflects a warming environment and longer growing season, but these long-term assemblage changes were more muted when compared to the warmer Cape Herschel ponds. Taken together with previous studies, this research further demonstrates the sensitivity of diatoms to climatic changes. M.Sc. Thesis Arctic Cape Arctic Ellesmere Island Nunavut Sea ice Queen's University, Ontario: QSpace Arctic Canada Cape Herschel ENVELOPE(-74.575,-74.575,78.587,78.587) Ellesmere Island Nunavut Pim Island ENVELOPE(-74.430,-74.430,78.725,78.725) |
institution |
Open Polar |
collection |
Queen's University, Ontario: QSpace |
op_collection_id |
ftqueensuniv |
language |
English |
topic |
Paleolimnology High Arctic Cape Herschel Diatoms |
spellingShingle |
Paleolimnology High Arctic Cape Herschel Diatoms Melnik-Proud, Rachael Diatoms as Bioindicators of Environmental Change in Cape Herschel and Pim Island (Nunavut, Canada) Ponds |
topic_facet |
Paleolimnology High Arctic Cape Herschel Diatoms |
description |
Thesis (Master, Biology) -- Queen's University, 2016-02-25 13:36:41.386 The High Arctic is especially sensitive to climatic change, but typically direct long-term monitoring data are lacking. Instead, paleolimnological approaches are now widely used to reconstruct past environmental changes. In particular, sub-fossil diatoms are well-established paleo-indicators of past limnological conditions. My thesis research is focused on Cape Herschel, east-central Ellesmere Island, as the numerous ponds in this region are well-studied and encompass a spectrum of morphometry, microclimate, and vegetation. This thesis has two separate but related chapters. The first chapter documents recent limnological changes and associated epilithic and surface sediment diatom assemblages from five well-studied Cape Herschel ponds, sampled on a semi-regular basis from 1987-2011. Diatom trends were reconstructed and compared to a suite of water-chemistry variables. Increased species diversity in both epilithic and surface sediments were observed, indicative of warming and associated longer ice-free growing seasons, allowing for the establishment of taxa with more complex lifestyles. These ponds also experienced increases in conductivity, dissolved organic carbon, dissolved inorganic carbon, and pH over the sampling period. Trends in diatom assemblage were more pronounced in epilithic samples (representing year-to year changes), when compared to surface sediments (an integration of multiple years of diatom production). Diatom assemblages from the Cape Herschel ponds were then compared to previously studied and near-by (~10 km away) Pim Island ponds. The latter ponds had a more muted response to recent climate warming, likely due to their colder microclimates linked to their close proximity to near-shore sea ice. The second chapter focused on diatom assemblages from sediment cores recovered from two Pim Island ponds. Diatom assemblages in both sediment cores recorded a recent shift from low diversity benthic fragilarioids to more diverse assemblages dominated by epiphytic taxa, with more complex growth forms. This shift in taxa and diversity reflects a warming environment and longer growing season, but these long-term assemblage changes were more muted when compared to the warmer Cape Herschel ponds. Taken together with previous studies, this research further demonstrates the sensitivity of diatoms to climatic changes. M.Sc. |
author2 |
Smol, John P. Biology |
format |
Thesis |
author |
Melnik-Proud, Rachael |
author_facet |
Melnik-Proud, Rachael |
author_sort |
Melnik-Proud, Rachael |
title |
Diatoms as Bioindicators of Environmental Change in Cape Herschel and Pim Island (Nunavut, Canada) Ponds |
title_short |
Diatoms as Bioindicators of Environmental Change in Cape Herschel and Pim Island (Nunavut, Canada) Ponds |
title_full |
Diatoms as Bioindicators of Environmental Change in Cape Herschel and Pim Island (Nunavut, Canada) Ponds |
title_fullStr |
Diatoms as Bioindicators of Environmental Change in Cape Herschel and Pim Island (Nunavut, Canada) Ponds |
title_full_unstemmed |
Diatoms as Bioindicators of Environmental Change in Cape Herschel and Pim Island (Nunavut, Canada) Ponds |
title_sort |
diatoms as bioindicators of environmental change in cape herschel and pim island (nunavut, canada) ponds |
publishDate |
2016 |
url |
http://hdl.handle.net/1974/14084 |
long_lat |
ENVELOPE(-74.575,-74.575,78.587,78.587) ENVELOPE(-74.430,-74.430,78.725,78.725) |
geographic |
Arctic Canada Cape Herschel Ellesmere Island Nunavut Pim Island |
geographic_facet |
Arctic Canada Cape Herschel Ellesmere Island Nunavut Pim Island |
genre |
Arctic Cape Arctic Ellesmere Island Nunavut Sea ice |
genre_facet |
Arctic Cape Arctic Ellesmere Island Nunavut Sea ice |
op_relation |
Canadian theses http://hdl.handle.net/1974/14084 |
op_rights |
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada ProQuest PhD and Master's Theses International Dissemination Agreement Intellectual Property Guidelines at Queen's University Copying and Preserving Your Thesis Creative Commons - Attribution - CC BY This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
op_rightsnorm |
CC-BY |
_version_ |
1766303612650127360 |